由溶致液晶制备高强高模纤维素纤维

工业生产的三醋酯纤维素(分子量约 10～5)溶解在三氟乙酸(TFA)和二氯甲烷(CH_2CI_2)混合溶剂中,在一定浓度下可形成液晶。选择了不同条件进行液晶纺丝,再把初生纤维经过235℃热处理,通过不同皂化处理,得到强度为11.02cN/dtex,模量为 348.98cN/dtex的高强高模纤维素纤维。X-光衍射分析表明该纤维素纤维属于纤维素I族。     

水溶性纸的溶解机制研究

采用吸附动力学模型对水溶性纸的水吸收过程进行表征,实验结果表明:其准一级吸附动力学模型的相关系数(R~2)0.95,水吸收过程主要受物理吸附控制.同时,利用聚焦光束反射测量仪(FBRM)对水溶性纸在水中的溶解行为进行全程实时监测,通过对整个溶解过程的纸页结构、纤维尺寸与形态的分析,可将其分为3个阶段:纸页的主体解构阶段(t_0～t_1)、纸页的解构和CMC纤维溶解阶段(t_1～t_2)、CMC纤维的溶解阶段(t_2之后).在水溶性纸的溶解过程中,纸页的主体解构阶段(t_0～t_1)是控制其溶解效率的关键阶段.     

聚环氧氯丙烷特性粘数的测定——聚环氧氨丙烷在环已酮及α—氯萘两溶剂中特性粘数之间的关系

氯醚胶,或称氯醇胶,是六十年代初出现的一种新型特种橡胶,它是由环氧氯丙烷经开环聚合(得“均聚胶”)或与其它单体开环共聚(得“共聚胶”)而成的。环氧氯丙烷的均聚物是一种结晶性高聚物,溶解性能较差。用溶液粘度法测定其分子量时,不易找到合适的溶剂。现今常用的方法是先测定它在环已酮溶液中50℃下的比浓粘度(η_(SP)/C)_(CH),按式(1)换     

富勒醇聚醚聚氨酯的热性能

通过水溶性多羟基化合物C60(OH)n和聚醚聚氨酯(PEO—PU)预聚体反应合成了一系列新型的C60星形聚醚聚氨酯，并用傅里叶红外分析(FTIR)、差式扫描量热分析(DSC)、热重分析(TGA)等手段对其性能进行了表征．结果表明，C60星形聚醚聚氨酯比线性的聚醚聚免酯具有更高的柔顺性和热稳定性；随着聚氧化乙烯数均分子量Mn的增加，C60星形聚醚聚氨酯的玻璃化转变温度(Tg)降低，热分解温度(td)提高．     

新型钠离子电池正极材料Na(Ni_(0.5)Mn_(0.5))O_2的制备和电化学性能

以CH_3COONa,Ni(CH_3COO)_2·4H_2O和Mn(CH_3COO)_2·4H_2O为原料,经过溶解、干燥和焙烧,得到产物Na(Ni_(0.5)Mn_(0.5))O_4.利用XRD,SEM对材料进行了结构和形貌的分析,结果显示产物含有少量的NiO相,呈片状形貌,颗粒小于5μm,有一定程度的团聚.对材料进行了不同倍率的充放电性能测试,产物展示了较好的电化学性能,0.1,0.2,0.5,1和5倍率时的放电容量分别为124,121,116.7,110.1和73.8mA·h/g.产物在2.0~4.0V电压区间充放电循环30次后,室温和55℃下的容量保持率分别为94.8%和91.1%,显示具有较好的高温性能,可以作为钠离子电池正极材料.     

超高分子量阴离子聚丙烯酰胺的合成

以丙烯酰胺(AM)、丙烯酸(AA)单体为原料,采用复合引发体系,通过水溶液聚合,制备出了特高分子量聚丙烯酰胺.研究了聚合体系的pH值、催化剂、链转移剂和氧化还原引发体系对聚丙烯酰胺分子量与溶解性能的影响.并通过正交实验得出了最佳工艺条件.当pH值为6.8,催化剂用量为0.05%,链转移剂为0.01%,引发剂用量为0.4%,在此条件下合成得到的聚合产品分子量高达8 900万,产品溶解性能好,20 min内可以完全溶解.     

包覆矿物纤维特性及其加填纸性能研究

通过化学方法在CaCl2-CO2-H2O体系中将轻质碳酸钙(PCC)粒子沉淀在矿物纤维表面,实现对矿物纤维表面包覆,借助于扫描电子显微镜(SEM)观察了CaCO3包覆矿物纤维的表面形态,分析了包覆矿物纤维表面化学组成及形态变化对纸机网部磨损的改善;以矿物纤维/重质碳酸钙(GCC)为填料,研究了包覆前后矿物纤维/GCC填料、助留体系及包覆矿物纤维与GCC配比对填料在纸张中的留着及纸张性能的影响.研究结果表明,包覆后的矿物纤维表面存在很多细小的CaCO3颗粒,颗粒大小在纳米级,随着包覆量的增加,原矿物纤维颗粒表面的细纹、棱角被填充及包覆,其表面化学成分及形态的改变可在一定程度上减小其对纸机的磨蚀.与原矿物纤维/GCC加填纸比较,加填包覆矿物纤维/GCC的纸张灰分更高,且其对纸张强度性能影响甚小.在本研究范围内所使用的两种包覆矿物纤维中,包覆量相对较大的包覆矿物纤维Ⅱ在纸张灰分提高27.2%的同时,纸张强度性能未受到影响.阳离子淀粉、阳离子聚丙烯酰胺(CPAM)和硅溶胶的助留体系对包覆矿物纤维/GCC留着高,对纸张的强度性能影响相对较小.在相同加填量条件下,随着填料中包覆纤维配比的提高,不仅纸张中填料留着显著增加,而且对纸张强度性能的负面作用也相对较小.     

聚对苯二甲酸乙二醇酯-聚四亚甲基醚多嵌段共聚物的Mark-Houwink-Sakurada方程

本文采用了四氯乙烷-甲醇和三氯乙烯-庚烷两组具有不同溶解性能的分级体系,利用交叉分级方法对聚对苯二甲酸乙二醇酯-聚四亚甲基醚多嵌段共聚物(PET-PTMG)进行分级。测定了各级分的数均分子量,在氯仿溶剂中,30℃时的特性粘数以及分子量多分散系数(M_W/M_n)。结果表明,在PET含量由14.4%—26.0%,数均分子量由1×10~4—1×10~5范围内,PET-PTMG可近似用一个MHS方程表征特性粘数与分子量关系。[η]=4.60×10~(-2)M_η~(0.09)试样的数均分子量M_n可由下式计算[η]=4.60×10~(-2)(M_W/M_n~(0.58)M_n~(0.69)在订定MHS方程时,考虑了级分试样的分子量多分散性修正。     

聚酯—聚氨酯溶液的C—13NMR 弛豫研究(2)自旋晶格弛豫与温度的相关性

本文对由聚己二酸丁二醇酯(数均分子量为2000),4,4二苯基甲烷二异氰酸酯(MDI)和扩链剂1,4一丁二醇形成的聚氨酯溶液的 C—13NMR 自旋晶格弛豫时间(T_1)与温度的相关性进行了研究,在氘代二甲基亚砜溶液中,应用JEOL FX—60Q 核磁共振仪测定了不同温度下(40—90℃)聚氨酯链上不同嵌段上 CH_2及 CH 碳的 T_1值,利用所得数据对聚氨酯分子链运动随温度的变化及结构与性能的关系进行了分析和讨论。     

液体除臭剂

本发明的除臭剂是由马来酸或马来酸酐与氯化亚铁或硫酸亚铁组成的。这种除臭剂可使用于家庭空气清洁器中,亦可用浸渍纸、布、纤维制成除臭纸、除臭布和除臭纤维。配方之一是:将13克氯化亚铁溶解在100毫升水中,加入2克马来酸,溶解后得到除     

THE APPLICATION OF CATIONIC POLYACRYLAMIDE AS DRAINAGE AND RETENTION AIDS

INTRODUCTIONIn recent years, with the rapid development of paper-making technology[1], such as improvement of pa-per-machine speed, extensive use of high yield and recycling pulp, and more closed white water systems, the environment of papermaking has changed greatly and this has brought many problems, Such as water temperature increasing and water quality becoming worse, large amount of fines in pulp, and more and more aninonic trash in pulp and water. These causes drainability of pulp a…     

改性微粒硅溶胶的研制及应用机理研究

The preparation and their application in papermaking of aluminium modified silica sol (AMS) and boron modified silica sol (BMS) were first investigated in China. At the same time the structures and configurations of AMS and BMS were first time authenticated. The modified silica sol microparticle system was detailedly and systemically studied with colloid charge titration. On the research of flocculation mechanism the laser sizer was also first time used to determine the floc size. Results showed that sodium silicate was treated and acidification was carried out by means of strongly acid cation exchange resins and obtained almost sodium free acid sols. The acid sol obtained after acidification was then made alkaline.     

APPLICATION OF CATIONIC POLYMERIC MICROPARTICLES ON RETENTION AND DRAINAGE

1.INTRODUCTIONThe microparticles retention and drainage technologywas brought in 1980s. It brings striking effect whenused in wet-end in paper-making. The retention offines and fillings and the drainage of pulp improved alot, meanwhile, the evenness also improved. So, mi-croparticles retention and drainage system is the maindeveloping direction of retention and drainage aids on paper-making industry.All microparticles in microparticle system we use currently are inorganic anionic. It rea…     

STUDY OF COORDINATED PRETREATMENT OF XYLANASE AND LACCASE ON SODA-AQ WHEAT STRAW PULP BEFORE CEH BLEACHING

INTRODUCTIONXylanase pretreatment can produce many small holes on pulp surfaces and cross section by removing part xylose that may be sucked back or exists in style of LCC. Thus penetrability of following chemicals. Olsen [1] observed coordinated pretreatment of xylanase and lignin enzyme (compound of lignin peroxide enzyme and manganese peroxide enzyme) had better delignification than sole xylanase and sole laccase lignin enzyme. So we can forecast that coordinated pretreatment of xylan…     

聚乙烯胺在CaCO3加填造纸中的作用效果

探讨了在弱碱性条件下聚乙烯胺(PVAm)对CaCO3加填的芦苇浆和废纸浆的助留助滤效果．实验结果表明：PVAm在两种浆中都有非常显著的助滤．助留效果，且在芦苇浆中的助滤效果大于废纸浆．PVAm在芦苇浆中对纤维的助留效果不如废纸浆，但对CaCO3的助留效果高于废纸浆．     

RELATIVE IMPORTANCE OF WOOD DENSITY AND CARBOHYDRATE CONTENT ON PULPING YIELD AND PRODUCT QUALITY

INTRODUCTIONPulp quality depends on wood quality and pulping process conditions. Wood quality is a result of forestry management practices and a combination of genetic, physical, anatomical and chemical characteristics of the wood [35]. Eucalypt pulps are desired for printing and writing and for tissue paper grades due to their anatomical and chemical characteristics. It has been shown that wood density exerts significant influence on pulp quality [21]. This parameter, together with volum…     

ENZYMATIC BLEACHING OF WHEAT STRAW SODA-AQ PULP BY LMS TREATMENT

Laccase has been proven that it has a good selectivity and efficiency in pulp bleaching. In this paper, the effects of LMS (Laccase Mediator System) treatment on delignification and bleaching of wheat straw pulp at various conditions, such as laccase dosage,temperature, oxygen pressure and pH, were investigated. The TCF sequence including LMS can bleach the wheat straw pulp to 81% ISO brightness with good strength. The synergetic biobleaching of LMS and xylanase of wheat straw pulp was also investigated. It was found that the final brightness and strength of synergetic biobleaching pulps increased to a certain extent and the bleaching selectivity was improved. The combination of the enzymes is feasible for the delignification and bleaching.     

MODIFIED OPAL:A NOVEL STABILIZER FOR HYDROGEN PEROXIDE BLEACHING OF PULPS

The possibility of modified opal as the stabilizer of hydrogen peroxide bleaching was investigated. The results showed that the modified opal in place of sodium silicate as the stabilizer of hydrogen peroxide bleaching is feasible. At the same dosage, above 3% ISO can be increased for both wheat straw pulp and deinked pulp. The stabilizing ability of the modified opal to hydrogen peroxide bleaching of pulp is improved markedly. It is favorable for bleaching to increase temperature and time within a permissive extent. The suitable process conditions are 10% of pulp consistency, 3% of hydrogen peroxide, 1.5% of sodium hydroxide, 3% of the modified opal, 70℃ and 60 min when the modified opal is used as the stabilizer of hydrogen peroxide bleaching. At these conditions, the brightness gain can reach about 16% ISO for wheat straw pulp. In addition, it is favorable for bleaching to add a little magnesium sulfate when the modified opal is used as the stabilizer of hydrogen peroxide bleaching, the brightness of pulp can increase I%ISO if0.05% of magnesium sulfate is added. The cost analysis indicated that the modified opal is superior to sodium silicate as the stabilizer of hydrogen peroxide bleaching in economical aspect and has further the potential of market development.     

轻型装饰原纸的研制：助剂与工艺条件优选

在实验室条件下,以漂白硫酸盐针叶木浆与棉浆试制轻型装饰原纸。对WS-01,02,03湿强剂、三聚氰胺甲醛树脂、阳离子型与阴离子型聚丙烯酰胺和A-RA_1助留剂、A-DS_1干强剂以及不同类型的二氧化钛进行了优选试验。结果表明,WS-01湿强剂与A-DS_1干强剂配合使用,可以使轻型装饰原纸的干、湿强度、吸水高度与灰分含量达到规定的质量要求。试验确定了主要影响因素与优化工艺条件。     

碱抽提强化的麦草浆二氧化氯漂白及ECF漂白流程研究

摘要：采用四种不同的碱抽提方式对麦草浆二氧化氯漂白(D0)进行强化,考查了不同碱抽提方式的强化效果,并对不同ECF漂白流程进行了对比研究。结果表明：在D0ED1漂白流程中,不同碱抽提方式对D0木素的修饰效果不同,就后续D1漂段而言,四种不同碱抽提模式下纸浆的可漂性顺序为：D0EOP>D0EP>D0EO>D0E。在D0ED1漂白流程中,D1段ClO2对白度的提升是有限的,达到白度极限后再增加ClO2用量对白度提高不明显。本实验条件下D1段ClO2用量以1.0%~1.2%为佳。从D0ED1与D0EP各漂白流程的对比来看,在终段漂白中以P取代D1效果要好,表明H2O2用于终段漂白其效果要好于ClO2。从其它ECF漂白流程的对比来看,D0EPP和D0EOPP流程漂白效果优于其它流程。本实验条件下采用D0EPP和D0EOPP漂白流程,麦草浆漂后白度可分别达到83.8%和85.7%。